Best Pick
eBayeBay Brand Central⚠ DIM +17 lb
3” eBay Sticker – Red, Blue, Green and Yellow — 500 Stickers
18″ × 14″ × 12″
+$36.10 USPS Ground Advantage · 19 lb billed
$0.09
each
pack of 500 · $45.00
← NiceBoxFinder
Buy →
Buy →
Buy →
Buy →
Buy →
Cheapest 18×14×12 padded mailer
Compare real eBay prices for 18×14×12 shipping boxes with DIM-weight-aware shipping estimates.
Live eBay listings — sorted by cost per useful box
Buy →
eBayeBay Brand Central⚠ DIM +17 lb
Comic Book Mailer Filler Pads — 50 Corrugated Sheets
18″ × 14″ × 12″
+$36.10 USPS Ground Advantage · 19 lb billed
$0.48
each
pack of 50 · $24.00
eBay⚠ DIM +17 lb
GRAINGER APPROVED 11A767 PK 25 Shipping Box,18x14x12 in 11A767
18″ × 14″ × 12″
+$36.10 USPS Ground Advantage · 19 lb billed
$1.32
each
pack of 25 · $33.00
eBayeBay Brand Central⚠ DIM +17 lb
Packaging Tape – Color Logo — 36 rolls
18″ × 14″ × 12″
+$36.10 USPS Ground Advantage · 19 lb billed
$2.27
each
pack of 36 · $81.72
eBayeBay Brand Central⚠ DIM +17 lb
Tissue Paper – Red, Blue, Green, and Yellow Multi-Pack 20” x 30”
18″ × 14″ × 12″
+$36.10 USPS Ground Advantage · 19 lb billed
$1.64
each
pack of 20 · $32.80
eBay⚠ DIM +17 lb
18X14X12 Cardboard Boxes-25 Pack
18″ × 14″ × 12″
+$36.10 USPS Ground Advantage · 19 lb billed
$2.08
each
pack of 25 · $52.00
Showing 6 of 12 real listings. Want all of them with custom quantity and weight? Search now →
What fits in a 18×14×12 box
A 18 × 14 × 12 inch box holds 3,024 cubic inches (1.75 cu ft) of interior space, putting it in the large-category. It's a popular choice for shipping items like multiple pairs of shoes, small appliances, clothing bundles — things that fit comfortably within those dimensions while leaving room for protective padding. Large boxes at this size are usually sold in smaller bulk packs — 10 to 25 — because storage and shipping of the empty stock itself becomes a consideration.
Shipping math for this size
Shipping cost for this size depends heavily on dimensional weight. For a 18×14×12 box, UPS and FedEx Ground compute a DIM weight of 22 lbs using their 139 divisor, while USPS Ground Advantage uses a 166 divisor, giving 19 lbs. Carriers bill whichever is greater — your actual weight or the DIM weight. USPS's higher divisor makes it roughly 3 lbs cheaper than UPS/FedEx for this size when your item is light, which is why our search results factor in DIM-weight automatically instead of just showing sticker prices.
How to pick the right pack size
When buying a 18×14×12 box, the biggest cost lever isn't which retailer you pick — it's which pack size you commit to. A 100-pack typically costs 2-3× more than a 25-pack but brings the per-unit cost down by 40-60%. Our ranking is based on *cost per useful box*, which gives bonus boxes partial credit — so a 100-pack can still win for single-box needs if the per-unit price is low enough, but a 25-pack often ranks higher when you only need a few. Every listing below links to a real eBay product page; we don't show placeholder results.
Search with your own dimensions
Pre-filled with 18×14×12. Adjust weight, quantity, or size as needed — we'll re-rank for your exact scenario.